The normalize property of the ConvolverNode interface is a boolean that controls whether the impulse response from the buffer will be scaled by an equal-power normalization when the buffer attribute is set, or not.
Its default value is true in order to achieve a more uniform output level from the convolver, when loaded with diverse impulse responses. If normalize is set to false, then the convolution will be rendered with no pre-processing/scaling of the impulse response. Changes to this value do not take effect until the next time the buffer attribute is set.
A boolean.
The following example creates a convolver node and assigns it an AudioBuffer. Before assigning the audio buffer, it sets normalize to false.
const audioCtx = new AudioContext();
// …
const convolver = audioCtx.createConvolver();
// …
// Grab audio track via fetch() for convolver node
try {
const response = await fetch(
"https://mdn.github.io/voice-change-o-matic/audio/concert-crowd.ogg",
);
const arrayBuffer = await response.arrayBuffer();
const decodedAudio = await audioCtx.decodeAudioData(arrayBuffer);
convolver.normalize = false; // must be set before the buffer, to take effect
convolver.buffer = decodedAudio;
} catch (error) {
console.error(
`Unable to fetch the audio file: ${name} Error: ${err.message}`,
);
}